The present invention relates to a fuel injection system and pertains more particularly to a valve arrangement in an injection system to prevent cavitation.
Fuel injection systems must employ a rather sharp fuel cutoff at the injector nozzle to avoid dribbling which in turn causes poor combustion and waste of fuel. When high injection pressures and high engine speeds are used, this sharp cutoff can cause large pressure fluctuations in the lines between the injection pump and the nozzle. This can cause cavitation when pressure in the injection lines drops below the vapor pressure of the fuel.
The known prior art approach to such problem is to dampen the secondary pressure waves developed in the system. This approach utilizes a plurality of restricted passages to dampen the pressure waves while permitting fluid flow. This approach is exemplified by the following U.S. Pat. Nos. 2,888,876 issued June 2, 1959 to Nichols, and 3,364,863 issued Jan. 13, 1968 to Olszewski, et al.
The major drawback to this approach is that it hampers high speed operation of an engine. The restrictions reduce flow rates necessary for such high speed operation.